Construction is being carried out mostly to the east of the West Bank separation barrier, and it began shortly after warrants were issued on November 26, suspending construction.
Haaretz's correspondents touring the area on Wednesday witnessed work being carried out in two industrial zones, as well as housing construction in Ariel and three other settlements.
A sign at one of the settlements announced plans for the construction of 65 new housing units, the report said.
No inspectors present
Israeli patrols were evident, but inspectors of the Civil Administration department in charge of enforcing the construction ban were conspicuous by their absence.
Civil Administration has made it clear that "warrants for the suspension of construction" are relevant only for buildings for which the foundations were not laid on the day a warrant was issued.
In all the sites, Haaretz
reporters found evidence of heavy equipment preparing the ground for construction or for the creation of suitable infrastructure.
In most of the work sites, the construction is being carried out by Palestinian labourers.
Yesh Din and Peace Now, two Israeli non-governmental organisations (NGOs), have found that construction is being carried out in more than 50 settlements and in two other industrial zones.
The building boom ironically kicked off while the US was demanding a "construction freeze" in the settlements, the two groups say.
The local authorities issued a great number of new construction permits, mostly to isolated and relatively small settlements, but also in the larger settlements.
On December 7 a tender was published for the sale of a large plot for the construction of a commercial structure.
One of the NGOs also recorded the takeover of Palestinian farmland by settlers near several settlements.
In a dozen settlements, there was evidence of construction having been stopped, possibly because of the warrants on freezing building, or because the settlers had rushed to create facts on the ground before the order went into effect and stopped temporarily, Haartez said.
Around 3,000 housing units, whose foundations had been laid at the time the order went into effect, have not been affected by the temporary suspension in settlement growth.
These are in addition to 492 housing units already approved by Ehud Barak, the Israeli defence minister.
East Jerusalem housing
In December, in move that elicited strong Palestinian and US criticism, the Israel housing ministry approved plans to build almost 700 new apartments in three illegal settlements in East Jerusalem.
And in November, Israel gave its approval for 900 new housing units in another settlement in the same area.
Palestinians have refused to reopen peace talks, which broke down a year ago, until Netanyahu halts all settlement construction in the West Bank and East Jerusalem.
Palestinians claim East Jerusalem as the capital of any future state and consider Jewish neighbourhoods there to be settlements.
East Jerusalem was annexed after the 1967 Middle East war, a move not recognised by the international community.