The doctor who treated Mo Farah with a controversial infusion is set to give evidence to MPs on Wednesday.
The infusion of the legal supplement L-carnitine, given to Farah before the 2014 London Marathon, is being looked at by the US Anti-Doping Agency (Usada) to determine whether rules were broken.
Dr Robin Chakraverty carried out the treatment on the instruction of Farah's American coach Alberto Salazar.
He will appear before the Culture, Media and Sport Committee (14:30 BST).
Chakraverty, formerly chief medical medical officer for UK Atletics (UKA), now works with the England men's football team.
MPs are also expected to hear from UKA head of endurance Barry Fudge as part of their ongoing investigation into doping in sport.
Fudge works closely with Farah and Dr John Rogers, a medic for the British athletics team who reportedly raised concerns about Salazar's methods.
Rogers and UKA chairman Ed Warner, plus UK Sport chief executive Liz Nicholls, are also due before the committee.
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Salazar has been under investigation by Usada and UK Anti-Doping (Ukad) since 2015, following claims of doping and unethical practices made in a BBC Panorama programme.
In March 2017, the BBC reported that UK Athletics staff may not have properly recorded the infusion of L-carnitine - a naturally occurring amino acid often prescribed as a supplement for heart and muscle disorders.
The BBC understands that staff failed to centrally log key data into the UK Athletics system, and investigators have therefore been unable to establish beyond doubt what the infusion levels were.
A spokesperson for Farah said his infusion was "well below" the 50 millilitre limit permitted under the World Anti-Doping Agency (Wada) code.
An interim Usada report centres on claims a number of athletes at Salazar's Nike Oregon Project were given infusions of L-carnitine - some of which were "almost certainly" more than 50ml and therefore doping violations.
Salazar and Farah, Olympic champion in both the 5,000m and 10,000m in 2012 and 2016, have strongly denied breaking any rules.
Farah was given the infusion during preparations ahead of his full London Marathon debut, in which he finished eighth.