KABUL, Feb. 25 (Reuters) - The Taliban on Sunday released Herbert Fritz, an 84-year-old Austrian and far-right nationalist who was arrested in Afghanistan last May.

The Austrian government said in a statement Fritz arrived in Doha earlier in the day after mediation by the Qatari government helped to secure his release.

After his arrest last year, Austria's Der Standard newspaper said Fritz had gone to Afghanistan and reported positively on life there. This helped fuel anti-immigration arguments that Afghanistan was a safe country to which refugees could return, the paper said.

The Taliban arrested him on suspicion of spying, Der Standard said.

The Austrian foreign ministry said it had been working to secure Fritz's release since May, and thanked Qatar and the European Union representation in Kabul for assisting its efforts to bring about his return to Austria.

Fritz was a founding member of the country's National Democratic Party (NDP), an extreme right group banned in 1988, according to Der Standard and other media.

Austria's far-right Freedom Party, which has been leading opinion polls ahead of parliamentary elections due later this year, had pressed for Fritz's release. The party has said he was researching a book in Afghanistan.

Qatar's foreign ministry expressed gratitude to Afghanistan's Taliban administration for its cooperation in releasing the Austrian, without naming him.

The Documentation Centre of Austrian Resistance, which monitors far-right activity, described Fritz as an active participant in extreme-right political circles.

Fritz was not immediately reachable for comment.

Photo from Reuters