Green Party TD Mr Ciaran Cuffe has said he believes he is being "pilloried" after a media report which claimed he was linked to an erotic website.
Mr Cuffe said he was seeking legal advice on yesterday's Evening Herald story that he had bought shares in a condom manufacturer which reportedly also advertises sexual toys.
The TD was previously criticised for owning shares in major oil companies linked to pollution and the exploitation of workers in developing countries. He was the Green Party's environmental spokesman at the time.
Mr Cuffe now owns shares in Condomi, a German company. "I am happy to invest in a company which manufactures condoms," he said. Condomi carried out valuable work with voluntary organisations, UN agencies, and the South African government in fighting the HIV/Aids epidemic, he added.
On the death of his mother Patricia several years ago, the Green TD inherited €1.4 million in shares. He faced criticism earlier this year when it was disclosed that these included investments in oil and chemical corporations and companies working in the Third World.
He then sold these shares and re-invested in what he said were ethical funds. Some of the companies generate solar power. However, erotic material, including sexual toys with a religious motif, is reportedly accessible on Condomi's website.
Commenting on media reports on his investment in the German condom company, Mr Cuffe claimed he was being unfairly treated.
"I feel I am being pilloried. I am taking legal advice on the story which was in the Evening Herald. If there are companies in the fund that do not comply with the ethical criteria used, I will raise this issue with the fund manager," he said.