The source of the rumors is the report, released to the public on
February 11, written by the team that operates the LIGO project.
The observational data presented in the report was collected in
September of 2014. Since then, it was circulated to Physicists
and other scientists all over the world, who all worked on it, analyzed
it, and tried to prove it wrong. Then the report was written, and
the report had to be read, reviewed, and criticized or approved,
by many scientists in related fields. The outcome was that there
was general agreement that the team accomplished what the report
says they did, and that they actually did observe gravity waves
17 months ago.
So it's a little bit more than a rumor.