The former Wimbledon and French Open champion had been provisionally suspended since October 2022 after testing positive for banned blood-booster roxadustat at the US Open last year where she lost in the first round.
Halep was "shocked and disappointed" and blamed contaminated supplements, adding that she "refused to accept their (ITIA) decision of a four-year ban" which runs until October 6th, 2026.
"I am continuing to train and do everything in my power to clear my name of these false allegations and return to the court," Halep said in a statement to Reuters.
"I intend to appeal this decision to The Court of Arbitration for Sport and pursue all legal remedies against the supplement company in question."
The ITIA said earlier on Tuesday it came to its conclusion based on the collection and analysis of 51 blood samples provided by Halep.
"The first (charge) related to an Adverse Analytical Finding (AAF) for the prohibited substance roxadustat at the US Open in 2022, carried out through regular urine testing during competition," the ITIA said in a statement.
"The second charge related to irregularities in Halep's Athlete Biological Passport (ABP)."
Halep strongly denies knowingly taking roxadustat and said she had evidence to show small amounts of the anaemia drug entered her system from a contaminated licensed supplement.
"The tribunal accepted Halep's argument that they had taken a contaminated supplement, but determined the volume the player ingested could not have resulted in the concentration of roxadustat found in the positive sample," the ITIA said.
It added that the ABP charge was also upheld as three independent experts were unanimous that "likely doping" was the explanation for the irregularities in Halep's profile.
"The volume of evidence for the tribunal to consider in both the roxadustat and ABP proceedings was substantial," Karen Moorhouse, CEO at the ITIA, said.
Halep had previously accused the ITIA of seeking to further delay her independent tribunal doping hearing and said she was being denied her right to be heard.
SUPPLEMENT CONTAMINATION
Halep explained how she adjusted her nutritional supplements ahead of the hard court season last year following recommendations from "my trusted team and physiotherapist".
"None of the listed ingredients included any prohibited substances. However, we now know - and the tribunal agreed - one of them was contaminated with roxadustat," she said.
Halep also accused the ITIA of bringing an ABP charge after the expert group learned her identity, saying that two experts changed their opinion in favour of ITIA's allegations.
"The ITIA relied solely on the opinions of these experts who looked only at my blood parameters - which I've maintained for more than 10 years in the same range," she said.
"This group ignored the fact no prohibited substance has ever been found in my blood or urine samples with the sole exception of one August 29 positive test for roxadustat."
Halep explained that since she had tested negative three days earlier, the exposure could only have been accidental.
Moorhouse said the ITIA had followed the proper processes in accordance with the World Anti-Doping Code.
"The panel recognised that appropriate procedure had been followed within the written decision," Moorhouse said.
The Professional Tennis Players Association (PTPA), which has 24-time Grand Slam champion Novak Djokovic on its executive committee, said the "repeated and unexplained delays" in Halep's case were "unfair and unacceptable."
"The PTPA is fully committed to supporting her in any future appeals, as well as all players who require assistance," it said in a statement.
"As indicated in our PTPA Principles, we will also continue advocating for improved processes moving forward, for the benefit of all."
The WTA said it was important for players to be aware of the sport's Anti-Doping Programme rules.
"The decision may be appealed to the Court of Arbitration for Sport. The WTA will support the decisions reached through the process and will continue to follow this closely," it said.
