By Nathan Layne July 7 (Reuters) - A Pennsylvania Republican lawmaker and ally of former President Donald Trump said on Wednesday he would try to launch a probe of the 2020 election in the battleground state, although a state agency urged counties not to comply with what it called a "sham review" of past elections. In a move that parallels a contentious audit going on in Arizona, state Senator Doug Mastriano said he sent letters to "several counties" seeking information needed for a "forensic investigation" of the November presidential election and of municipal primaries this past May. Democratic President Joe Biden won the state by about 81,000 votes, four years after Trump's victory there helped propel the Republican to the presidency. The state legislature remained in Republican hands.