I became involved in this issue after reports from doctors in a developing country that three papers in a systematic review published by my company may have been fabricated.
The papers in question had co-authors in two other countries and so I contacted them.
One co-author replied that he had concerns, but as none of the studies was conducted in his country, he had no data. He said he was unaware of the papers until Dr X told him they had been accepted in the journals.