BERLIN, May 22 (Reuters) - Concern that more than one thousand people were wrongly granted asylum by Germany's migration agency may lead to personnel changes at the agency, the interior minister signaled on Tuesday.The minister, Horst Seehofer, told a newspaper an investigation was underway at the Bremen office of the agency, and he would make decisions about "organizational and, if necessary, personnel changes" next week."I'm doing all I can to get to the bottom of it," Seehofer told Mittelbayerische Zeitung, saying that an internal report by the Federal Office for Migration and Refugees (BAMF) showed that mistakes had also been made at other offices besides Bremen.The report that one thousand migrants may have been granted asylum even though they fell short of the required criteria has resonated politically in Germany where a flood of migrants, mostly from the Middle East, is seen as having helped boost support for the far right."A great deal must be done, not only in Bremen," Seehofer said, adding that the agency had received initial tipoffs about problems in the agency's Bremen office as early as 2016.Seehofer's ministry, which approved his words as published by the newspaper, said BAMF was investigating 10 of its 70 outposts, affecting some 8,500 cases.Der Spiegel magazine reported that BAMF Director Jutta Cordt was informed about problems as early as February 2017 .BAMF did not comment on the number of offices being investigated but confirmed the agency's leadership had received an initial email about reviewing the Bremen asylum applications.Seehofer told the newspaper he would welcome a parliamentary investigation, but would also investigate the issue with "no regard" for reputations of people or institutions.More than 1.6 million migrants, many from the Middle East, have arrived in Germany since 2014, becoming a political issue which helped propel the far-right Alternative for Germany into parliament for the first time in last year's election.The AfD has called for a wider parliamentary investigation of Chancellor Angela Merkel's handling of the migrant crisis.Lars Klingbeil, secretary general of the center-left Social Democrats, junior partners in Merkel's coalition government, told the Rhein-Necker Zeitung newspaper that Seehofer should act "quickly and comprehensively" to address the problems."The mass granting of wrongful asylum decisions is absolutely unacceptable," he said.In April, prosecutors said they were investigating the former head of BAMF's Bremen office, who is suspected of granting asylum to some 1,200 people who did not qualify for it, the majority of them members of the Yazidi ethnic group.Linda Teuteberg, a senior member of the Free Democratic Party (FDP) also backed a parliamentary investigation, telling broadcaster Deutschlandfunk that Seehofer "can't keep using the excuse that he's new on the job. The responsibility is growing with every day."