Obviously, they extended it as they might want to have more time to do the investigation. Since there is full pay, let them take their own sweet time. If you are found not guilty, they should restore your full pay for the 2 weeks suspension period. If you are found guilty and you are not happy with their decision, you can appeal to the Labour Department.
Read Section 14 for info:
"14. Termination of contract for special reasons.
(1) An employer may, on the grounds of misconduct inconsistent with the fulfilment of the express or implied conditions of his service, after due inquiry:
(a) dismiss without notice the employee; or
(b) downgrade the employee; or
(c ) impose any other lesser punishment as he deems just and fit, and where a punishment of suspension without wages is imposed, it shall not exceed a period of two weeks.
(2) For the purposes of an inquiry under subsection (1), the employer may suspend the employee from work for a period not exceeding two weeks but shall pay him not less than half of his wages for such period;
Provided that if the inquiry does not disclose any misconduct on the part of the employee the employer shall forthwith restore to the employee the full amount of wages so withheld..."