But many believe the government had allowed six floors to be added to a completed building. Internet users dubbed The Praia 'the biggest illegal structure in Macau'.

New Tenhon chairman Liu Chak-wan's status as an executive councillor and his friendship with former chief executive Edmund Ho Hau-wah has only added to the controversy surrounding approval.

Liu said his company applied for six additional floors in late 2005 - before construction began.

He said the Land, Public Works and Transport Bureau had approved the change at the end of 2005 by letter. 'Such letters have legal effect,' Liu said.

Liu said the tower was perfectly legal and dismissed descriptions of it as an illegal structure as nonsense. 'We followed all the standard procedures,' he said.

'How can my project possibly be an illegal structure?'

The Praia sits on a 10,756 square metre site on Doca Seca Road beside the Inner Harbour.

Approving construction projects long after they are completed has become a common practice of the Macau government in the last few years as a backlog of land-use applications builds up while officials tread warily in the wake of the graft scandal involving former public works minister Ao Man-long.

The land-use approval for Sands China's US$4.42 billion project on the Cotai Strip, often referred to as Parcels Five and Six, was gazetted on Wednesday - four years after construction began and five years after the government received the application for the project.

Political commentator and columnist Anthony Wong Dong said the government was habitually late in gazetting its approval for private projects.

'A lack of transparency in the approval process often adds to suspicion that some people have gained advantages by using their influence,' Wong said.

Legislator Au Kam-san, a veteran critic of Macau's land policies, said the green light given to The Praia had called into question the government's campaign to crack down on illegal rooftop structures.

'People feel it unfair that their rooftop flats are targeted while The Praia is left alone,' Au said.

Thousands of illegal flats have been built on buildings in Macau's old neighbourhoods.

Such structures are commonly seen on 40- to 50-year-old residential buildings where top-floor owners have the right to the rooftop but are not allowed to build any unauthorised structures.

Both Liu and Wong said Macau's biggest graft scandal had slowed down the government's approval for private projects as public works officials were being extra-careful not to make mistakes.

In April last year, former public works minister Ao was jailed for 28 years and six months on 81 counts of bribe-taking, money laundering and other crimes involving hundreds of millions of patacas.

'After the Ao trial, [public works officials] dared not speed up on a lot of procedures,' Liu said.

Jaime Roberto Carion, director of the Land, Public Works and Transport Bureau, on May 7 admitted that his bureau was 'a little slow' in approving land-use changes.

'The process of changing land uses is a little slow. We will review it and speed it up,' Carion said.

A bureau spokesman said the government had been improving transparency in land-use approvals.

'We are speeding up the revision of the Land Law and other relevant laws and regulations,' he said.

The Ao scandal weakened people's trust in the administration, after a trial in the Court of Final Appeal found Ao had ridden roughshod over guidelines laid down for the administration, overruling the rating of bids for public projects, changing the city's alignment rules to suit developers and leaking the government's infrastructure plans.

The court heard in November 2007 that height limits set by urban planning authorities could often be changed to fit developers' plans.

Fall from grace

Former minister Ao Man-long was jailed when convicted of this many charges: 81