Sunday Life can reveal that members of the Real IRA hatched the plan to murder Alexander Success after it emerged that he had approached the daughter of a top dissident to participate in a sham marriage.

And we can reveal Success is also believed to have made more than £25,000 from the series of scams.

Our exclusive pictures show a laptop computer, blank payslips, marriage documents, driving licences, birth certificates and fake passports discovered by detectives at Success's Londonderry home.

Mountains of evidence were gathered by cops — who received help from the Gardai, Home Office, Forensic Science Agency and Immigration officials — during their painstaking two-year investigation.

The African conman made legal history last week when he became the first person in Northern Ireland to be jailed for paying strangers to marry both here and in the Republic.

The fake weddings took place at the Guildhall, Coleraine, Letterkenny and Stranorlar in Co Donegal.

The 30-year-old, who faces deportation from Northern Ireland after his release from prison, received a four-year sentence for organising bogus marriages and assisting illegal immigration to a EU member state.

Along with fellow countryman Akeem Olugbenga Shittu, the pair netted thousands of pounds from the fraud. A number of local men and women were also found guilty of assisting illegal immigration and are currently awaiting sentence.

Success, a former computer student at the University of Ulster, masterminded the scam after he was approached by a key figure from the Chinese mafia in Dublin.

Shittu, who lost citizenship of the Republic because of his conviction, originally lived in Dublin and was the link man between Success and the Chinese crimelords. The crooks were paid thousands to by the Far East crime-gang to help their friends and relatives gain legal entry to the UK and the Republic.

But Sunday Life can also reveal how Success:

l Used FIVE different identities during his time here;

l Preyed on young women in hostels, bars and clubs;

l Paid 'Mr Gay Derry' Eamonn Johnston £2,000 to marry a Chinese woman;

l Was threatened by the Real IRA;

l Is suspected of involvement in identity theft scams; and

l Is believed to have made more than £25,000 from arranging the marriages of strangers.

The top cop who brought the Nigerian schemer to justice, Detective Sergeant Tim McCullough, told how it was only through a "stroke of luck" that police were able to uncover Success's trail of fraud and deception.

DS McCullough, who works for the Police Service's organised crime department, has been an officer for 15 years, but this is the first time he has worked on a case involving bogus marriages. He said: "Success was known to police for committing a number of driving offences, but his bogus marriage scam only came to light after he was stopped at a routine checkpoint.

"He tried to say he was someone else, but the officers knew him. He then produced a false passport and that's why we conducted a search of his home.

"We discovered a wide range of computers, scanning equipment, blank payslips and documentation which convinced us these men were involved in facilitating sham marriages.

"This was a complex investigation involving hundreds of documents and mutual assistance with a variety of different agencies.

"Everyone who worked on the case deserves great credit because this was the first one of its kind to be brought before the courts in Northern Ireland."

The top cop also denied claims that the local people who participated in the scams were "vulnerable".

He added: "These people were not vulnerable. They were offered huge amounts of money to participate in these weddings and they knew what they were doing.

"They knew they were breaking immigration laws with the marriages, but they still persisted with them.

"These people received between £1,800 and £3,000 for each wedding, but they would have got more cash if they could have provided bills and addresses with the names of the strangers they were marrying.

"Success was very clever and he would have given these people clear instructions on what way to perform and act when they were going through with the marriages.

"He encouraged the people he paid, for example, to put on the tears and to look into each others' eyes as a way of publicly declaring their love for each other.

"There was also one occasion when he got so cocky that he attended one wedding in Donegal before dashing across the border to arrange another one in Londonderry on the same day.

"Success was very clever and there's no doubt he manipulated people. This man knew how to work the system and had a keen interest in immigration. He was a facilitator for getting people into the UK and the Irish Republic.

"He may have pleaded guilty to arranging a number of weddings, but there's no doubt there could be more which we may never know about.

"This man made a fortune from this illegal enterprise, but it's just so hard to put an exact figure on the cash he received. I'm not in a position to comment on other cases of a similar nature we may be involved in."

Senior republican sources in Derry claim the fraudster was forced to flee the Galliagh area after dissidents were made aware of the scam.

Said one source: "He [Success] was approached by the dissidents in Galliagh and told to leave the area because he was suspected to trying to recruit women in the area for the sham marriages. If he had returned to the area he would have been shot because the dissidents were not happy at the amount of money he was making.

"He was also involved in other crimes and the locals didn't want him getting involved in any of their own scams."

We also understand many of Success's contacts in the underworld went into hiding after his arrest.

Interpol was also used in the probe but no history of Success's background could be found in his homeland.

Shittu also formed close links with gangsters in Leeds and Liverpool and helped dozens of people gain legal status in the UK through the bogus marriages.

And it's believed Success, which may not be his real name, forged links to a fellow Nigerian in Scotland who arranged similar weddings.

Lamin Manneh, who admitted breaching immigration law by arranging sham marriages, matched up African students who wanted UK citizenship with people from the Paisley area. Said a Scots police source: "Manneh had contacts all over the UK, including Northern Ireland.

"We think he may have been introduced to Success through a third-party and the pair were able to exchange information on their various scams.

"We know that Success had contacts in Dublin and London and that he was keen to extend his scam because he knew there was big money to be made."