(Corrects president's name to Edgar in third paragraph)
* Political tensions high in Africa's No. 2 copper producer
* Lawyer says blocked from seeing detained opposition leader
* Police deny they are barring such access
By Chris Mfula
LUSAKA, April 13 (Reuters) - Zambian police on Thursday denied the main opposition party's claims that its detained leader Hakainde Hichilema had been denied access to his lawyers and family but his lawyer insisted this was the case.
Hichilema was arrested on Tuesday and charged with treason for allegedly obstructing Lungu's motorcade, raising the political temperature further.
Relations between government and opposition in Africa's No. 2 copper producing country have been tense since August, when President Edgar Lungu's Patriotic Front (PF) party beat Hichilema's United Party for National Development (UPND) in a vote the opposition says was rigged.
The two men are old rivals and Lungu has beaten Hichilema narrowly in two presidential elections, including last year's by a razor-thin margin.
"We have not blocked lawyers and Mr Hichilema's members of the family from visiting him because that is his constitutional right," police spokeswoman Esther Mwaata-Katongo said, responding to a claim by the UPND.
Hichilema's lawyer Jack Mwiimbu said he had seen his client on Wednesday but had since been prevented from visiting him.
"There are instructions for him not to be seen by anybody without authority from police headquarters. We have therefore started processing court papers. We want the court to compel the police to allow us to see our client," Mwiimbu told Reuters.
Mwiimbu also said Hichilema had complained on Wednesday of feeling unwell after police fired tear gas into his house when he was arrested.
On Saturday, Lungu passed through Mongu, 500 km (300 miles) west of the capital Lusaka, and his motorcade was obstructed because Hichilema refused to give way, police said. Zambia's economy has been depressed for years by low commodity prices, mine closures, rising unemployment, power shortages and soaring food prices that Hichilema blames on mismanagement by Lungu. (Writing by Ed Stoddard; Editing by James Macharia and Tom Heneghan)