The Flood tribunal is expected to investigate whether Mr Liam Lawlor last week destroyed documents he had been ordered to give to the tribunal.
Fine Gael has also called for a Garda investigation following a report that Mr Lawlor burned credit card statements and other papers at his Lucan home last Tuesday.
A Government spokesman said last night of the report in the Sunday World: "If it's true it's very serious for Liam Lawlor." There was no corroboration of the report available yesterday.
The burning allegedly took place in the grounds of Mr Lawlor's house the day before he went to jail for contempt of the order directing him to hand over documents concerning all his bank and credit card accounts.
According to the Sunday World, some of the documents being burned blew on to the road outside Mr Lawlor's home and were given to the newspaper. Documents reproduced by the paper yesterday include credit card bills in Mr Lawlor's name dating from 1998 to as recently as last month as well as other correspondence related to business dealings.
However, legal sources said the Flood tribunal would certainly seek to find out whether such an event took place, and whether any documents covered by the discovery order were destroyed. "It would have very serious repercussions for him," according to one senior legal source, if relevant documents had been destroyed. This would raise the prospect of his being accused of further contempt and of obstructing the tribunal.
Mr Justice Smyth in the High Court last Monday jailed Mr Lawlor for three months for contempt, suspending all but one week of the sentence while ordering him to co-operate fully with the tribunal.
Fine Gael's justice spokesman, Mr Alan Shatter, said yesterday the Sunday World report may require action by the Flood tribunal and the courts, as well as the Garda.
If Mr Lawlor had indeed destroyed documents he was supposed to give to the Flood tribunal, this would confirm Fine Gael's view that he should be called on to resign his Dail seat immediately.
"These allegations require that the Tanaiste and the Progressive Democrats reconsider the appropriateness of the motion they have agreed with the Taoiseach, to be voted on when the Dail reconvenes next week."
The Government motion says Mr Lawlor should resign his Dail seat should he fail to co-operate with the Flood tribunal within the timetable set out by the High Court. This could give him up to November - the month to which the remainder of Mr Lawlor's sentence was suspended - to co-operate before the call on him to resign is made. This, Mr Shatter said yesterday, amounts to a period of "political probation".
In an RTE Radio interview yesterday, the Tanaiste, Ms Harney, repeated her view that Mr Lawlor's position was untenable and that he should resign his Dail seat. However, she made no mention of any timescale. A spokesman for her confirmed, however, that the motion effectively post-dating the call on him to resign is the agreed Government position.
The spokesman declined to comment on the implications of the Sunday World report, saying it was a matter for the tribunal to consider.
The Labour leader, Mr Ruairi Quinn, said at the weekend that his party would not support the Government motion, which is nevertheless expected to be passed with the backing of the four Independents who traditionally support the Government.
It not known whether Mr Lawlor will speak or vote on the motion, and, if so, whether he would support the Government.
Mr Quinn said he would oppose the Government motion as it "seeks to defer until November next a decision as to whether the Dail should request Liam Lawlor to resign his seat".