Prince George’s County Police raided a house in College Park Tuesday morning, an official confirmed Wednesday.

A department K-9 unit alerted police of a controlled dangerous substance in a package at the post office, said Prince George’s Police spokesman Cpl. Lamar Robinson. Police tracked the package to a house on the 7500 block of Dickinson Avenue at 10:50 a.m. and conducted a contents search with permission of a resident in the house, he said.

Police are investigating whether the house was affiliated with any University of Maryland fraternities.

A contents search does not require a search warrant but is done with permission of an individual at the property. Controlled dangerous substances are drugs that can be used for medical and nonmedical purposes, such as marijuana, heroin or cocaine. The drugs are classified in schedules that determine risk level of abuse or dependence.

The investigation is ongoing, and it is unclear what police found in the house or if any arrests were made, Robinson said.

“My understanding is that it is an ongoing investigation … I do not have any more information at this time,” Ross Brannigan, this university’s Interfraternity Council president, wrote in an email Tuesday.

A man who answered the door at the house at about 2:30 p.m. Tuesday refused to confirm or deny the raid occurred.

This article will be updated as more information becomes available.

Diamondback reporter Jay Reed contributed to this report.