A Donegal TD is raising serious concerns over how 13-thousand retired civil servants and some government ministers had errors around pension payments.

It's understood most ministers are affected and the majority owe money to the state, while others are due money.

The sums range from hundreds of euro to just above 30-thousand euro, and the error is now under investigation.

Donegal Deputy and Sinn Fein's Finance Spokesperson, Pearse Doherty says it's very concerning.