LONDON (AP) _ A former official at the Irish Embassy pleaded guilty Monday to charges he provided falsified passports to foreigners in return for cash and sex. Southwark Crown Court sentenced Kevin McDonald to 21 months in jail.

Witnesses told the court that McDonald, 35, charged up to $24,000 for a passport normally available for $100, and he made $400,000 in six months.

McDonald, who was the chief passport officer for the Irish Embassy in London, pleaded guilty to conspiring with other unidentified people to obtain false passports between January 1986 and May 1987.

''In return for thousands of pounds, he supplied passports to virtually anyone, no matter how bogus or sham their applications were,'' said prosecutor Julian Bevan.

The official also demanded sexual favors from Moroccan prostitutes to whom he sold passports, the prosecutor said. He said the official was photographed in bed with two of them.

In sentencing McDonald, Judge Marcus Anwyl-Davies said the official had breached the trust of his employers. The judge ordered him to pay $5,680 in legal costs.

Holding an Irish passport allowed McDonald's customers to stay in Britain for an unlimited time and easily visit other countries, said Bevan.

He said Irish passports are granted legally to people with an Irish parent or grandparent or others who are married to an Irish citizen.

McDonald put details from legitimate birth and marriage certificates on application forms and used them to issue the false passports, Bevan said.

The scheme was exposed when a reporter from The People newspaper, a London weekly, sent a South American woman posing as the mistress of a wealthy businessman to see McDonald, accompanied by a woman reporter. Their conversation was secretly recorded.

When the story was published, McDonald fled to Dublin. He was arrested in August 1988 and extradited to Britain for prosecution.

The case also led to several trials last year of people described as McDonald's customers and agents.

One of his operatives, French-born Collette Raud, said at one of the earlier trials that McDonald supplied passports to people from Libya who might have been terrorists.