Germany's Nobel literature laureate Günter Grass, who earlier this year was barred from Israel for criticising its nuclear policy, has written a poem praising the nuclear whistleblower Mordechai Vanunu.

Vanunu, a former technician at Israel's secret nuclear plant near Dimona, spent 18 years in prison – much of it in solitary confinement – after leaking details of the country's nuclear programme to the Sunday Times in 1986. Grass's new collection of poetry, Eintagsfliegen, published in Germany last week, describes Vanunu as a "role model and hero of our time" who "hoped to serve his country by helping to bring the truth to light", and calls on Israelis to "recognise ... as righteous" the man "who remained loyal to his country all those years", according to German reports.

In April this year, Grass angered Israel with a poem in which he wrote that "Israel's nuclear power is endangering / Our already fragile world peace". He later clarified this, saying that he actually intended to criticise Israel's current government, but the damage was done, with Israel declaring the Nobel laureate persona non grata for his "attempt to fan the flames of hatred against the state of Israel and its people, and thus to advance the idea to which he publicly affiliated in his past donning of the SS uniform". Grass, who won the Nobel in 1999, served as a teenager in the Waffen SS during the second world war, a fact he revealed in 2006.

Speaking about Grass's new collection, Israel's foreign ministry spokesman Yigal Palmor told German broadcaster Deutsche Welle that "it is refreshing to note, given Grass's past positions, that there is at least one Israeli who finds grace in his eyes".