NEW YORK (CBSNewYork/AP) — New York City’s special investigation commissioner says allegations of grade changing and test tampering by city teachers and school administrators have more than tripled since 2003.

The commissioner, Richard Condon, attributed the rise to the higher stakes attributed to standardized tests and to the increase in the number of schools to 1,700 from 1,200 in 2002.

“For a number of years you had bonuses being paid to schools that did better and that is one possible reason why there was an increase,” Condon told 1010 WINS.

His data showed that allegations of cheating rose to 225 last year from 68 in 2003.

Schools Chancellor Dennis Walcott said he didn’t believe that the increase in allegations meant more misconduct was occurring.

In an interview with The New York Times, he credited the ease of reporting a complaint anonymously through email and stronger whistle-blower protections. He also noted that Condon proved only a few cases of cheating each year.

(TM and Copyright 2011 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2011 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)