Taxation of employee on secondment to uk

Hi

An Indian IT company sends its employee to UK on a work permit on secondment. The period of stay is 90 days.

During this period he is on the payroll of the UK company. He gets salary and allowance as per his indian salary converted into GBP. Tax is also deducted on the salary. No indian salary or allowances are paid to him during this period of 90 days.

The employee returns back to India and his indian salary starts from the day he arrives in India.

With reference to A.Y. 2015-16 

1. Is there any tax liablity on th UK salary

2. Should the UK salary income be disclosed in the returns filed in India. 

3. Are there any specific returns to be filed in UK.

Thanks

Ninad