Tánaiste Michael McDowell has met British Home Secretary John Reid in Brussels, where they discussed the death of former Russian spy Alexander Litvinenko.
Mr Reid was to brief his European Union counterparts on the case today as detectives investigating prepare for their trip to Russia.
Both he and Mr McDowell met privately this morning. It is not known whether the illness that struck former Russian prime minister Yegor Gaidar in Dublin last week was also on the agenda.
After conflicting reports on the cause of Mr Gaidar's illness there were suggestions that the two cases were linked.
Mr Gaidar, now an influential liberal academic in Russia and critic of Russian President Vladimir Putin, collapsed with what his daughter described as a "mystery illness" while attending a conference at the NUI at the end of last month.
He was treated at the James Connolly Memorial Hospital.
Mr Gaidar and Mr Litvinenko are not thought to have met recently, but it has been speculated that both were in contact with a mutual associate in recent weeks.
Mr Reid arrived for a two-day meeting of the EU's justice and interior ministers in Brussels this morning, insisting that the wider health risks of Mr Litvinenko's radiation poisoning were "minimal".
A team of nine officers from Scotland Yard's counter-terrorism unit will fly out to Moscow later today to continue their inquiries into the former spy's death last month.
They are planning to interview those who met Mr Litvinenko (43) on the day he was allegedly poisoned in London with the deadly toxin polonium 210.