The Internal Revenue Service improperly withheld information from requesters after Freedom of Information Act requests were filed, according to a report from the Treasury inspector general for tax administration.

Auditors evaluated a sample of 70 FOIA requests and found that the agency improperly withheld information in 10 of these cases.

The IRS withheld publicly available information as well as information taxpayers wanted regarding their own cases such as tax information and examination reports.

"Although the IRS properly released thousands of pages from these documents, taxpayer rights may have been violated because the IRS improperly withheld information from the requestors," the auditors said.

Based on the sample of FOIA requests the IRS did not give full information for, the inspector general projects there may be 385 of the total 2,693 FOIA requests that had information withheld.

In addition, auditors found that sensitive taxpayer information was inadvertently disclosed when responding to some FOIA requests.

"During our review for improper denials, we identified four requests for which information was inadvertently disclosed (e.g., tax information from a year not covered by a Power of Attorney and a list of Employer Identification Numbers)," the report stated.

In response, the IRS said that they will continue to work towards improving their response to FOIA requests.

"The IRS remains committed to openness in government to ensure public trust and to support the ideals of transparency, public participation and collaboration," said Edward Killen, chief privacy officer at the IRS.

"We will continue to work towards further improving the processing of information requests in a timely and quality manner," said Killen. "It is important for the public to understand our offices process and release hundreds of thousands of pages in response to FOIA requests each fiscal year."