SCOTLAND'S friendly football match against Nigeria in London tonight is at the centre of an international investigation into suspected match-fixing.

The National Crime Agency (NCA), which probes serious and organised crime, contacted football's governing body Fifa after the Gambling Commission, the regulator for the bookmakers' industry, issued an alert over the World Cup warm-up match at Fulham's Craven Cottage ground. The fixture is under scrutiny because of activity on the Asian betting market. There is no suggestion anyone from the Scotland set-up is under suspicion.

It comes as Fifa continues its inquiries into claims by a convicted Singaporean match-fixer that he helped arrange the results of games in order for Nigeria to qualify for the 2010 World Cup. The body notified the Nigeria Football Federation that it would watch video tapes of all the matches Nigeria played to reach the tournament in South Africa.

The Scottish Football Assoction's (SFA) security and integrity officer, Peter McLaughlin, has been kept fully informed of the investigation concerning the match and has been in discussions with the NCA and Fifa.

"We have been liaising with the relevant authorities, the National Crime Agency and Fifa, and will be preparing for the match as normal," said chief executive Stewart Regan.

The commission issued an alert to betting companies to be particularly vigilant about irregular betting patterns around five other friendlies being played tonight. Apart from the Scotland game they are South Korea versus Tunisia; USA v Azerbaijan; Denmark v Sweden; and Mexico v Israel.

However, the Craven Cottage fixture, to be refereeed by Lee Probert, has come under particular suspicion. The intelligence passed on was not specific but was intended as a pre-emptive measure.

A spokesman for the crime agency said: "The NCA will from time to time provide operational detail necessary for public reassurance purposes. It does not routinely confirm or deny the existence of specific operations or provide ongoing commentary on operation activity."

Bookmakers William Hill said in a statement: "We've seen no evidence of the reported issues and we wouldn't expect to. This sort of activity will be executed in the illegal betting market, and is unlikely to be seen in the UK or European-regulated sector."

A Ladbrokes spokesman said: "We are taking bets on the match, and will continue to monitor the situation."

It comes amid concerns that various pre-World Cup games may be targeted by match-fixers on behalf of illegal betting syndicates, mainly based in the Far East.