BERLIN, Nov 20 (Reuters) - Germany has offered Warsaw the Patriot missile defence system to help it to secure its airspace after a stray missile crashed in Poland last week, Defence Minister Christine Lambrecht told a newspaper on Sunday.The German government had already said it would offer its neighbour further help in air policing with German Eurofighters after the incident, which initially raised fears that the war in Ukraine could spill across the border."We have offered Poland support in securing airspace - with our Eurofighters and with Patriot air defence systems," Lambrecht told the Rheinische Post and General Anzeiger.The missile that hit Poland last week, killing two people, appeared to have been fired by Ukraine's air defences rather than a Russian strike, NATO chief Jens Stoltenberg has said.German forces currently have 12 Patriot units, two of which are deployed to Slovakia."