Russian athletics chiefs and the sons of the former world body president Lamine Diack blackmailed athletes suspected of doping to let them keep competing, according to a secret World Anti-Doping Agency inquiry quoted by the Mediapart news website Thursday. Mediapart said it had seen a report by a WADA independent commission which is due to be made public next Monday. French police Tuesday charged former International Association of Athletics Federations president Diack with corruption over suspicions he took bribes for covering up doping cases. Mediapart said six Russian athletes, including top marathon runner Lilya Shobukhova, were the targets of blackmail attempts by Russian athletics federation officials. It quoted the WADA report as saying Shobukhova, who had her ban reduced after giving evidence to IAAF investigators, handed over $569,000 between 2012 and 2014 to a Russian coach Alexey Melnikov, who acted as an intermediary. The report added that Diack's two sons, Pape Massata Diack and Khalil Diack, were alleged to have asked for $500,000 from Turkey's 1,500m women's Olympic champion Asli Cakir Alptekin in November 2012, but she refused. Alptekin was suspended in April 2013 for abnormal blood samples and is now serving an eight-year ban and been stripped of her London Olympics and European titles. The WADA report says that the Diack family used a Singapore-based company Black Tidings for money transfers. The report said Lamine Diack was told several times about the activities of his sons but did nothing. The 82-year-old Diack was charged by French financial investigators Tuesday of corruption, money laundering and conspiracy. A source close to the investigation said Diack was suspected of taking money from Russian athletes. His legal advisor, Habib Cisse, and the IAAF's former anti-doping doctor, Gabriel Dolle, have also been charged with corruption. Pape Massata Diack resigned as an IAAF marketing executive in December last year after he was named in reports as having sought bribes. Valentin Balakhnishev, former president of the Russian athletics federation, also stood down as IAAF treasurer, over the allegations. Russia bans 5 The Russian athletics federation suspended five athletes Thursday, including a top marathon runner and an Olympic hammer throw finalist, just days before the publication of a major report into Russian doping. Marathon runner Maria Konovalova received a two-year ban and was stripped of results going back to 2009. She finished second at the Chicago Marathon in 2010 and third in 2013. Konovalova's ban casts a further shadow over the Chicago Marathon, where the winners of five of the last seven women's races have been banned in doping cases. Russian Liliya Shobukhova won the 2009, 2010 and 2011 events before she was banned in a separate doping case. Konovalova had originally crossed the line third in 2010 but was promoted to second when Shobukhova was excluded. The 2013 and 2014 winner, Kenya's Rita Jeptoo, has also been suspended for doping. Also Thursday, the Russian athletics federation said that hammer thrower Maria Bespalova, who finished 11th at the 2012 London Olympics, was banned for four years after testing positive for a steroid. Also banned were three lesser known Russian athletes: race-walker Evgeny Nushtaev and runners Vlas Bredikhin and Yaroslav Khlopov. — Agencies