Wednesday's swap of prisoners between Israel and Hezbollah planned was mediated over an 18-month period by a German secret agent.
TV images showed Hezbollah handing over the Israeli soldiers in black coffins
German involvement had been reported all along in the Middle East, but was not confirmed by Berlin until Tuesday, July 15.
Quoting an internal document compiled by Chancellor Angela Merkel's office, the sources said the "facilitator" was a staffer with the BND, the German foreign intelligence agency, who was authorized by the United Nations to manage the secret contacts.
Over the 18 months, he flew a total of 700,000 kilometers (435,000 miles), shuttling between UN headquarters in New York, Tel Aviv, Beirut and various European capitals.
Berlin calls exchange a "great success"
Four of the five Lebanese prisoners that will be exchanged for the two Israeli soldiers
The Berlin document said the deal was the deal was the fruit of "extraordinarily difficult" negotiations. It calls the deal a "great success" for the UN, the German government and the "excellent" German mediator himself.
The paper does not name the mediator, but Middle East news reports have regularly identified him as Gerhard Conrad, the BND officer who was assigned to broker the previous Israel-Hezbollah prisoner swap in 2004. He is respected and trusted by both sides and by the UN.
The deal is expected to come to fruition on Wednesday morning at Rosh Ha'Nikra/Naquora, the only border crossing between Israel and Lebanon, with the handover of the bodies of two Israeli soldiers, Eldad Regev and Ehud Goldwasser, who were seized in July 2006.
Israelis confirmed dead
According to Hezbollah sources, the five Lebanese prisoners set to be released have arrived at the Israeli side of the border crossing. Hezbollah also said Wednesday morning that the coffins of the two dead Israelis had already been handed over to Red Cross officials at the border, confirming for the first time that the soldiers had indeed died.
Regev and Goldwasser are ded
"Today we are handing to the International Committee of the Red Cross two coffins," senior Hezbollah official Wafik Safa told reporters at Naqoura, the Lebanese side of the border. "We are seeing that they are both dead."
Red Cross officials checked the coffins inside a tent on the Lebanese side of the Naqoura crossing after which they were taken to the Israeli side of the border to be handed over to Red Cross delegates there.
German agent Conrad earlier had met with Lebanese officials and then with Israeli officials on each side of the border, informing them of the soldiers condition.
The families of the two Israeli soldiers reacted with sorrow to the news that they were dead.
"Many years of worry, suffering and great pain came to an end today, when unfortunately we received our sons as fallen soldiers and not as living sons," Shmulik el-Grably, a spokesman for the families, told DPA news agency.
He especially thanked Conrad, whom he said the families had met in secret several times, for his "relentless efforts."
German mediation to continue
The document notes that the negotiated swap is not the end of BND mediation, since Germany has promised Israel continuing assistance in finding out what happened to other missing Israeli personnel, as has already been provided for the past 15 years.
However, the German program apparently does not extend to the case of Gilad Shilat, the Israeli soldier kidnapped two years ago by the Hamas movement, which controls the Gaza Strip, the sources said.