BBC media correspondent Nick Higham reports on the "faking" claims

The latest allegations, in the Guardian newspaper, refer to the "Inside Castro's Cuba" programme made by the same producer, Marc de Beaufourt.

The newspaper says that the programme-makers' claims that they had secured "rare access" to the Cuban President Fidel Castro and an "elusive interview" with him, were untrue.

de Beaufort: unavailable for comment

It alleges that the film of President Castro used in the hour-long documentary was actually archive footage supplied in good faith by the Cuban Government.

The Guardian reports that the Cuban Government is angry about how the film was used and denies that President Castro has ever given an interview to Mr de Beaufort or Carlton.

The Cuban leader's personal cameraman, Roberto Chile, who gave Carlton the footage, is quoted as saying that the interview was "false".

The newspaper also says that an unnamed Cuban diplomat has called the programme - the winner of two international awards - "a fake".

It quotes a spokesman for the British television watchdog, the Independent Television Commission (ITC) as saying that passing off archive material as an interview could be a breach of its legally-binding code on programme standards.

Drugs programme called into question

The allegations follow the Guardian's accusations that parts of "The Connection" - a Carlton documentary which claimed to show a Colombian drugs baron operating from Britain - were faked.

The Guardian claimed Carlton's drugs documentary misled viewers

Among that documentary's contentious scenes was one in which a "drug courier" was seen swallowing scores of packages of heroin, then taking a plane to London and slipping into Britain.

But the Guardian said the packages did not contain heroin. It claimed the plane ticket for the "drugs mule" was paid for by Mr de Beaufort and that when the man arrived at Heathrow airport he did not get through customs, as was suggested, but was deported.

It also said that the mule's continuous journey from Bogata to London was filmed in two stages, six months apart.

One man described as the "number three" in an infamous drugs ring was actually a retired bank cashier with low level drug connections, the paper claimed.

Mr de Beaufort denied any wrong doing.

However, the Guardian says that "The Connection" is now being investigated by Carlton and the ITC.

Responding to the claims about "Inside Castro's Cuba", a Carlton spokesman said Mr de Beaufort was unavailable for comment as he was out of the country.