Cape Town – Nigeria's acting president Yemi Osibanjo has reportedly maintained that President Muhammadu Buhari is in "good shape", following reports on Monday that the 74-year-old leader had extended his stay in London for health reasons. Buhari, according to his spokesperson Femi Adesina, had written to the National Assembly on Sunday, "informing them of his desire to extend his leave in order to complete and receive the results of a series of tests recommended by his doctors". Reports indicated that Buhari has been dogged by speculation about whether he was physically fit for office even before he took power in May.He had been due to return to Abuja on Sunday after 10 days' holiday.In his first comments on the president’s health, Osibanjo said he had a "fairly long" conversation with Buhari on Monday and was "hale and hearty", a BBC said. Osibanjo, however, did not disclose details of the medical checks Buhari was undergoing in London.He said that Buhari "needs to go for a cycle of tests and once he sees the test results and gets medical advice, we should expect him very soon".This came as Nigerians pushed for clarity on the president’s health, with the main opposition Peoples Democratic Party (PDP) saying: "He [Buhari] should tell them (the public) the true state of his health." The announcement of Buhari’s prolonged stay in the UK triggered fresh speculation about the state of Buhari's health and has done little to convince an already sceptical public that there is no cause for concern.