The former striker said that when he called Mahama, the president of Ghana at the time, the president reacted swiftly to assist to save Castro.
Castro, whose real name was Theophilus Tagoe, and Gyan were close friends who recorded many songs.
But in July 2014, while on holiday at the Ada Estuary with Gyan, his brother Baffour, and other individuals, the singer vanished together with one Janet Bandu.
This came about following a strange event in which Castro and Miss Janet Bandu drowned while riding a jet ski in the Ada Estuary.
Nine years have passed since the event, and though the musician is still missing, Gyan disclosed that Mahama deployed ten helicopters in less than an hour after hearing of Castro’s drowning.
Speaking at the Bukom Boxing Arena during Freezy Macbones’ fight against Nigerian boxer Oladimeji Salami, Gyan expressed his gratitude for the former president’s kindness.
“One thing I remember during 2014 when my friend’s incident happened was Castro,” the former Sunderland forward said.
“I called him on the phone, and he asked me what he could do to help, and I told him anything he could do. I remember that within less than an hour, there were like 10 helicopters at Ada.