THE "Moscow letter" at the centre of the case would have caused a split in the Workers' Party if it had ever been brought to its attention, Mr De Rossa told the court.
He told counsel for Independent Newspapers, Mr Patrick MacEntee SC, that the letter - purporting to seek £1 million in funds from the Communist Party in Moscow - was not authorised by the Workers' Party.
He added that if such a letter had been brought before the political committee of the Workers" Party it would have brought about a split in the party long before 1992.
Mr De Rossa had earlier been giving evidence to the court about his visit to Moscow, with the then Workers' Party general secretary, Mr Sean Garland, in September 1986.
Mr MacEntee asked if there was any importance to be attached to the fact that the Moscow letter of September 15th, 1986, was addressed simply to the secretary of the Communist Party of the Soviet Union (CPSU), and did not have a further address. Did that support the contention that perhaps the letter was hand-delivered in Moscow?
Mr De Rossa said he did not know what it would contend. He knew that the letter of August 7th, (from Mr Garland to the CPSU) did have an address. Mr
MacEntee said yes, but that letter was sent from Dublin. Mr De Rossa replied that he did not know where it was sent from.
Mr MacEntee said he was asking if any significance could be "attached to the fact that the September 15th letter carried no address of any description, not even Moscow.
Mr De Rossa: "I have no idea, what significance could be attached to it. As I explained already to you, I had nothing whatsoever to do with this particular letter."
Mr De Rossa also said that when the letter appeared in full in The Irish Times in October 1992, he read it very carefully.
Mr MacEntee said he must have been very concerned to find out who had written it, but Mr De Ross, said no, the best way to establish that he had nothing whatsoever to do with it was to make that quite clear to everyone who asked him.
Mr MacEntee asked was it not "crystal clear" that it was a letter of Mr Garland's? Mr De Rossa said no.