The six Romanians on trial for the theft of valuable paintings from the Rotterdam Kunsthal are considering suing Rotterdam council and the museum, their lawyer said on Tuesday.

The trial recommences on Tuesday in Bucharest after two postponements – in August and September – when case notes from the Netherlands did not arrive in time.

Lawyer Catalin Dancu is preparing a case because of the delays and because he has his doubts about whether the stolen paintings were genuine, according to the Volkskrant.

Eugen Darie, one of the suspects, told the AD on Tuesday: ‘When we entered the Kunsthal to check it out, I saw absolutely no security, so I doubt the paintings were originals.’

The seven paintings, which include works by Monet, Picasso and Gauguin and with a total value of €17m, were stolen in October 2012. Their fate is still unclear.

Darie says he thought it was a joke when he heard how much the paintings were worth, says the AD. He also apologised for the theft.

Dancu not only blames the Dutch for the delays in the trial but also for their ‘narcisstic behaviour’. ‘Everything that goes wrong is blamed on the Romanian court system,’ he said.