NCAA investigators spent a large chunk of Sunday with Johnny Manziel questioning the Texas A&M quarterback about allegations from memorabilia dealers that he accepted payments for autographs a source familiar with the investigation told on Monday night. The governing body's officials met Sunday with Manziel the reigning Heisman Trophy winner for nearly six hours on the College Station Texas campus the source said. It was unclear whether the NCAA was satisfied with the initial meeting with Manziel or if it would require additional time with the redshirt sophomore. Texas A&M's season begins Saturday at home against Rice. Attorney Jim Darnell hired by Manziel's family did not return calls to ESPN's Brett McMurphy on Monday night seeking comment. In separate ESPN reports earlier in the month multiple autograph dealers told reporters Darren Rovell and Joe Schad that Manziel accepted payments to sign more than 4000 items including footballs and photographs. In his first season Manziel accounted for 5116 total yards and 47 touchdowns becoming the first freshman to win a Heisman Trophy. Manziel led the Aggies in their first year in the SEC to an 11-2 record that included an upset of eventual national champion Alabama and a Cotton Bowl victory against former Big 12 rival Oklahoma. When visited Texas A&M's preseason camp from Aug. 17-19 sources close to the program indicated that the school's administration had discussed whether to sit Manziel in the face of the ongoing investigation. In the days after that visit however the university's higher-ups strongly defended and backed the Aggies' star player. Chancellor John Sharp in an interview last week with a local TV station called into question the original reporting by ESPN and maintained Manziel's innocence. An ESPN spokesman issued a statement Thursday saying: "We stand by our reporting."