Submarines produced by Germany and supplied to Israel as part of an extensive arms deal are equipped to enable the launch of nuclear-tipped cruise missiles, the German weekly Der Spiegel reported on Sunday.

Get all the latest updates on Haaretz's Tumblr blog and Facebook page

Last month, Israel received its fourth Dolphin –class submarine from Germany, which is expected to become operational in 2013.

According to a senior Israel Navy officer speaking upon the arrival of the craft, the "submarine has a range for everything," adding that it needs to refuel and charge its batteries only once in a long while.

"This submarine can stay underwater for longer," he added, saying it had both "visible and invisible" abilities and was meant to operate in the Mediterranean.

The first three submarines were given to Israel by Germany in the late 1990s, with the German government footing most of the bill.

According to foreign reports, they are equipped with cruise missiles that have a range of 1,500 kilometers and can carry nuclear warheads. These reports say the submarines enable Israel to deliver a "second strike" in the event of a nuclear attack.

In its report on Sunday, a report in German weekly Der Spiegel, citing a months-long probe, confirmed that the submarines supplied by Germany were indeed fitted to enable nuclear-warhead carrying cruise missiles.

Under the headline "Secret Operation: Samson," the German weekly indicated that "after years of speculations as to the technical armament of the submarines Germany exports to Israel," experts in "Germany and in Jerusalem now confirm: They are armed with nuclear warheads."

"Berlin has known this for quite some time," the article added.

Defense Minister Ehud Barak told Der Spiegel in response to the article, “The Germans can be proud that they are ensuring the existence of the State of Israel for many years to come.”

In his column opening Sunday's Der Spiegel, Editor in Chief Georg Mascolo wrote that "months-long research proves that the submarines Germany supplies the Israeli navy make use of equipment to carry nuclear weapons."

"Now, German officials admit, since they know what the use Israel is making of German weapons," Mascolo added.

If the information acquired by Der Spiegel is indeed correct, it could cause quite a bit of embarrassment to German Chancellor Angela Merkel and her government, which have been consistent in their claim that the submarines provided to Israel are not nuclear.

The German left-wing has dispensed harsh criticism over the supply of the naval crafts to Israel, claims that Merkel has thus far been able to reject.

Most recently, the issue was stirred anew by famed German author Gunter Grass, who penned a poem severely critical of Israel's policies and of Germany's sale of submarines to the IDF.

In his poem "What must be Said," Grass said that “Israel’s nuclear potential has been stealthily growing for years,” without being under any kind of international supervision. Grass believes that Israel is planning to arm submarines recently purchased from Germany with nuclear warheads.

“Germany could be responsible for a crime that can be foreseen," Grass wrote.