The young family of a construction worker who was violently killed in the streets of Dublin is unlikely to receive mortality benefit of over €75,000 because the builder who employed him had not paid the necessary pension contributions.

Pensions ombudsman Paul Kenny is pursuing the builder for the money. Failing to pass on the deductions from builders' wages leaves builders open to criminal prosecution, Kenny warned. The worker was in his mid-30s with four dependent children and was violently ass­ault­ed by a gang near his home in early 2007. He died from head injuries in July that year.

Under the construction-industry pension scheme, the family of a construction worker who dies while in employment receives €63,500 death-in-service benefit and each dependant child gets €3,175. But like all pension schemes, if the contributions are not made, no benefit can be paid out.

The Pensions Board is separately investigating 250 cases where builders have failed to pay over contributions leaving thousands of builders without a pension at retirement or their families without mortality benefit if they die before that.

Despite the large number of investigations, the board has successfully prosecuted just one employer to date. Last year, it secured a High Court judgment against Limestone Construction for the recovery of €185,000 in pension deductions it had made from its 200 workers over 14 months but failed to pass on to the scheme.

After a cheque for half the amount agreed 'bounced', the board secured a warrant for the arrest of a Colm McNulty, a director of Limestone.

A spokesman for the Pension Board said that while the warrant is still active, McNulty has since fled to Canada.

While some of the ombudsman's cases would overlap with the board, Kenny said pension arrears was "a huge and growing problem in the construction industry".

The ombudsman said in the last 12 months complaints about builders failing to pass on pension deductions have almost quadrupled.

"I am pursuing up to 150 cases at the moment whereas there were just 35 cases in 2007," said Kenny.

About 10 cases at any one time concern workers who have died but whose families are unable to get mortality benefit because employers have failed to keep up payments.

Kenny added that while the problem has intensified in the wake of the collapse of the construction sector, he is still pursuing cases going back to the middle of the construction boom.

Kenny was also critical of builders who deploy solicitors to delay efforts to secure unpaid subscriptions.

"In one case a builder paid his solicitors €20,000 to unsuccessfully challenge my efforts to get €19,000 in unpaid pension contribution," he said.

"I will continue to pursue the cases of these builders who are exposing themselves to criminal prosecution."