A District Court judge has gone on trial at the Dublin Circuit Criminal Court charged with deception while she was a practising solicitor.

Heather Perrin of Lambay Court, Malahide, Co Dublin, has pleaded not guilty to inducing a client to leave half his estate to two of her children.

Opening the case this morning, prosecuting counsel Dominic McGinn said the alleged offence was uncovered when Ms Perrin was appointed a judge in 2009 and transferred her practice to another firm.

Mr McGinn said the case involved a client, Thomas Davis, who had been a friend for decades.

He had given instructions to leave €2,000 each to Ms Perrin's children and the bulk of his estate to his wife's nieces.

The trial was told Mr Davis signed the will, but did not read it as he trusted Ms Perrin.

He later requested a copy of the will, which took some months to be delivered to him. It appeared to be in order.

However, the solicitors who took over Ms Perrin's practice later discovered the original will, which contained the names of Ms Perrins two children as beneficiaries of the residual estate along with his wife's nieces.

Mr Davis told them this was not his intended will.

The residual estate included part of the proceeds from the sale of a house jointly owned by Mr Davis for €1.8m along with a large sum of money in a savings account.

Ms Perrin originally said the mistake was a secretarial error, but later told gardaí the will reflected Mr Davis' intentions.

The jury was also told the new legal firm O'Hanrahan Quaney had contacted Mr Davis because they were concerned about other documents unrelated to this trial, which they believed had not been drafted correctly.

He had written to them in response to say he did not want them to act for him. It emerged that these letters were drafted by Heather Perrin and sent on her advice.

The legal firm refused to hand over documents to a man who came to collect them as they had some concerns. It later emerged he was there on the instructions of Ms Perrin.

O'Hanrahan Quaney became concerned and checked through the documents when they found the will.

They thought it unusual that Ms Perrin's children were beneficiaries of the larger part of the will.

When they checked with Mr Davis he told them the will was incorrect.

The will was later changed but Mr Davis left in the bequest for €2,000 to each of Ms Perrin's children. The court was earlier told he knew them well and was fond of them.

Ms Perrin denies the charge. The trial continues at Dublin Circuit Criminal Court.