It’s been just’days since the announcement of the merger between the Center for Public Integrity and the Huffington Post Investigative Fund, supported by a grant from the Knight Foundation.

The merger has received coverage in The New York Times, The Guardian and many other news outlets. As part of its Investigative Reporting Initiative, Knight also’supported CPI in October with a $1.7m grant to complete a digital newsroom transformation, and then with an additional $250,000 to support the merger.

CPI also released a report this week on lawmakers who publicly opposed the stimulus plan but privately wrote letters seeking funds. (Between the’ merger news and the new investigative report, more than 60,000 unique visitors went to the CPI website on Monday.)

The release of the stimulus report was a partnership:’ CPI worked with The Washington Post, CBS, NPR and members of the Investigative News Network including MinnPost and the Florida Center for Investigative Reporting to get the content of that report the most coverage.

Also this week, nonprofit’investigative journalism powerhouse’ProPublica‘launched a report this week on payments received by doctors that link them to drug companies.’ They released this data and a series of reports in collaboration with five partners including the Boston Globe, Chicago Tribune, PBS and NPR.

On the west coast, the staff of California Watch at the Center for Investiative Reporting — the oldest of the big three nonprofit investigative journalism organizations funded by Knight Foundation — won the 2010 Journalists of the Year award from the Society of Professional Journalists Northern California Chapter for its role in watchdog reporting under the leadership of Louis Freedberg.