(1) A building worker who has been registered as a beneficiary under this Act shall cease to be as such when he attains the age of sixty years or when he is not engaged in building or other construction work for not less than ninety days in a year:
     Provided that in computing the period of ninety days under this sub-section, there shall be excluded any period of absence from the building or other construction work due to any personal injury caused to the building worker by accident arising out of and in the course of his employment.
     (2) Notwithstanding anything contained in sub-section (1), if a person had been a beneficiary for at least three years continuously immediately before attaining the age of sixty years, he shall be eligible to get such benefits as may be prescribed.
     Explanation.--For computing the period of three years as a beneficiary with a Board under this subsection, there shall be added any period for which a person had been a beneficiary with any other Board immediately before his registration.